use macos-13 instead of macos-11

Author: mattip

.github/workflows/posix.yml

@@ -18,16 +18,16 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-11]
+        os: [ubuntu-latest, macos-13]
         PLAT: [i686, x86_64]
         INTERFACE64: ['0', '1']
         MB_ML_VER: ['2014']
         MB_ML_LIBC: ['manylinux']
         include:
-          - os: macos-11
+          - os: macos-13
             PLAT: arm64
             INTERFACE64: '1'
-          - os: macos-11
+          - os: macos-13
             PLAT: arm64
             INTERFACE64: '0'
           - os: ubuntu-latest
@@ -42,7 +42,7 @@ jobs:
             MB_ML_VER: _1_1
         exclude:
           - PLAT: i686
-            os: macos-11
+            os: macos-13
           - PLAT: i686
             INTERFACE64: '1'
     env: